str06 = "python"
print(str06[2])  # t
print(str06[5], str06[-1])
# print(str06[6])  # IndexError: string index out of range
print(str06[1], str06[2], str06[3])  # yth
# str[start:end:step(步长, 如果不写step，默认值是1)]
print(str06[1:4])  # 含头去尾  yth
print(str06[1:4:2])  # yh
print(str06[:4])  # python: pyth, start 不写默认是字符串的开头
print(str06[2:])  # python: thon, end 不写默认是字符串的结尾
print(str06[5:2:-1], "-----")  # python  noh
print(str06[::-1])  # python: nohtyp
print(str06[:])  # python: python

str01 = 'Hello world'  # 17:25上课
str02 = "Who are my baby girl?"
print(str01)
print(str02)
# I'm your baby girl~
str03 = "I'm your \nbaby girl~"
print(str03, "======")
# 三引号：原样字符串
str04 = '''aaa   I'm your babygirl
       and my name is "nfx"'''
print(str04)
